In the conclusion to their article on rapidly cycling affective disorder, Coryell et al1 state that "knowledge of those factors that predispose to this condition or that prolong it would have substantial clinical importance."

In this regard, it is worth noting evidence that tricyclic antidepressants (TCAs) or other antidepressants may trigger rapid cycling in a subgroup of bipolar patients.2,3 However, Coryell et al conclude that "the evidence implicating TCAs in the genesis of rapid cycling is weak." They present three arguments against the evidence.

First, in their own data, Coryell et al found that nearly twice as many patients who became rapid cyclers (33%) as those who did not (18%) were treated with TCAs or monoamine oxidase inhibitors at the time of intake into their study. However, they concluded that "the use of TCAs or monoamine oxidase inhibitors did not seem to anticipate rapid cycling after statistical control